1. Field of the Invention
The present invention relates generally to the art of transport refrigeration units and in particular to outer protective covers for such units.
2. Description of the Prior Art
A typical transport refrigeration unit of the type designed for mounting on the front face of a tractor trailer unit comprises a one piece, self-contained fully refrigerant charged, prewired, refrigerant/heating unit powered by a diesel engine. In such a design the evaporator fits into a rectangular opening in the upper portion of the trailer front wall. When installed, the evaporator section is located inside the trailer; and the condensing section is outside and on the front of the trailer. The condensing section consists of an engine-compressor drive package, condenser fan, condenser coil, radiator coil, control panel, relay module, refrigerant controls, piping, wiring and associated components.
Structural frame means support all of the components and facilitate attaching of the unit to the trailer front face. Also supported by the structural framework is an outer cover which includes the necessary air inlet and outlet openings for cooling, and which may be opened to provide access to the interior of the unit for maintenance and service.
Such refrigeration units should be able to be manufactured without undue difficulty, should be as light in weight as possible while having adequate structural strength and should provide adequate refrigerant capacity for their intended service.
Looking now to the outer cover of such units it is considered desirable to provide components which are lower in cost and weight while at the same time displaying improved quality, appearance and reliability. It is also desirable to provide such components which are made from fewer parts thus facilitating handling at assembly.